I've never used Kohana before. This tutorial is my way of learning it. If you notice something wrong or something that can be done better, just write a comment and I'll try to fix it.
Also I'll borrow some parts of the code from another excelent Kohana 3 tutorial (http://www.dealtaker.com/blog/2009/11/20/kohana-php-3-0-ko3-tutorial-part-1/)

N.B. English is not my native language. But I'll try to write correctly.